Dark fiber is typically optical fiber infrastructure that is currently in place but is unused. For example, some electric utilities have installed optical fiber cable where they already possess right of way access for the installation of power lines; the expectation being that they can lease the infrastructure to telephone or cable TV companies, or use the fiber cables to interconnect their own offices. To the extent that these installations are unused, they are described as dark fiber. Often times, companies lay a significantly greater amount fiber than current capacity requires to curb costs of having to lay additional fiber in the future, as well as in anticipation of future expansion and utilization.
Conventionally, telecommunication service providers or companies (“telcos”) own or lease dark high capacity fiber optic lines. The dark fibers can be leased to individuals or other companies who want to establish optical connections among their own locations, e.g., private wide area networks (“WANs”). These fiber cables are sometimes re-sold or leased to a fiber lessee with service level agreements (“SLAs”), but without any attached technology; these dark fibers are typically lit by the fiber lessee. In these instances, the fiber is not controlled by the fiber owner/lessor, e.g., the phone company. Instead, the fiber lessee provides the necessary components to make the fiber functional. The fiber owner, however, must provide SLA guarantees without visibility into the dark fiber because a given owner does not have the necessary access to the dark fiber to monitor such service levels. There is thus a need to monitor dark fiber (as well as other resources lacking direct visibility) indirectly by inferential modeling and analysis.